Distal symmetric painful diabetic neuropathy is the most frequent clinical form of diabetic neuropathy. The condition appears as a result of alteration of the structure and function of nervous fibres as a consequence of hyperglycaemia. Hyperglycaemia determines the metabolism of glucose on alterative pathways and generates increased oxidative stress, mechanisms that cause an accelerated apoptosis of the neurons and a high intensity of lipid peroxidation. Pathogenic treatment of diabetic neuropathy includes limited options, two of them are: Benfotiamine (inhibits the metabolism of glucose on hexosamine pathway, reducing the formation of advanced glycosylation end products) and alpha-lipoic acid (has a scavenger effect on free radical species). The study included 120 patients with distal symmetric painful diabetic neuropathy randomized in 3 treatment groups. We evaluated the effect of oral administration for 8 weeks of Benfotiamine in a dosage of 300mg/day in monotherapy, of alpha-lipoic acid in a dosage of 600 mg/day in monotherapy, respectively of both -in combined therapy - on the parameters that are used to determine the severity of distal symmetric painful diabetic neuropathy: Diabetic Neuropathy Symptoms score, Neuropathy Disability Score and the intensity of lower limb pain on the visual analogue pain scale. All the three therapies were effective with a statistically significant improvement of these parameters, but the combined therapy with alpha-lipoic acid and Benfotiamine was superior to the monotherapy with alpha-lipoic acid or Benfotiamine.
Effects of DL-alpha-lipoic acid on peripheral nerve conduction, blood flow, energy metabolism, and oxidative stress in experimental diabetic neuropathy